Data processors are employed in electronic devices to execute tasks set forth in a set of program instructions. As the tasks become more complex or demand more precision, it is sometimes desirable to increase the bit-width of the data processor. For example, a 32 bit processor can typically execute tasks of greater complexity and greater precision than an 8 or 16 bit processor. Further, it is sometimes desirable for a data processor to execute programs designed for a processor having a lower bit-width, to provide backward compatibility for those programs. However, the manner in which backward compatible modes are defined can vary. For example, for a 64 bit processor, the 32 bit compatibility mode is sometimes defined so that 64 bit results and instructions are provided by and available to the 32 bit application. In other compatibility definitions, the 32 bit compatible mode only provides 32 bit results to the application. Although software can be designed to comply with multiple compatibility definitions, this can increase the software complexity and decrease its efficiency. Accordingly, there is a need for an improved data processor and methods thereof.